Evaporator structure



SePt- 13, 1949 c. c. HUBBELI. 2,481,512

EVAFORATOR STRUCTURE Filed July 2l, 1945 5 Sheets-Sheet l ZAL tARCH ROUN HUBBE Sept. 13, 1949.

1N VEN TOR. CHARLES C. HUBBELL BY @0216160 Sept. 1-3, 1949. c. c. HUBBELI.

EVAPORATOR STRUCTURE 5 Sheets-Sheet 3 Filed July 21 1945 INVENTOR. CHARLES C. HUBBELL. BY @M /dZ/v tAHUH RUUM 5 Sheets-Sheet 4 C. C. HUBBELL.

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Filed July 2l 1945 SEARCH RGN INVENTOR. CHARLES C. HUBBELL BY ,utv

C. C. HUBBELL EVAPORATOR STRUCTURE Sept. 13, 1949.

Filled July 2l, 1945 Patented Sept. 13, 1949 LHKUH iiUUlVl EVAPORATOR STRUCTURE Charles C. Hubbell, Cleveland, Ohio, assignor to The Yoder Company, Cleveland, Ohio, a corporation of Ohio Application July 21, 1945, Serial No. 606,367

9 Claims. (Cl. 62-126) This invention relates to refrigeration apparatus, particularly of the type employing a suitable refrigerant capable of being compressed from the gaseous state and liquied and then fed into one or more evaporators wherein it expands into a gaseous state and is then returned to the compressor for re-circulation to repeat the cycle. One of the difficulties affecting the eiciency of apparatus of this type is due to the mixture of the oil utilized in the operation of the compressor with the refrigerant during operation of the apparatus. During periods when the apparatus is shut-down, this oil adheres to the inner surfaces of the evaporator or becomes trapped in or adjacent angularly related passages in the evaporator, so that upon again operating the apparatus the normal circulation of the refrigerant is materially affected; that is, the circulation of the refrigerant through the evaporator is non-uniform as well as reduced and accordingly the absorption of heat is decreased, and the power required to operate the compressor is increased. In all apparatus of which I have knowledge no provision has been made for overcoming this difficulty or providing for the removal of the accumulated oil when the apparatus is again operated.

One object of the invention is to provide an improved evaporator which (a) insures a minimum accumulation of oil therein during operation of the apparatus, (b) prevents settling of the oil in the bottom portion of the evaporator when the apparatus is shut down and (c) provides for the circulation of the refrigerant through the evaporator in a manner, when the apparatus is again operated following a shutdown, to take up the oil that adhered to the surfaces of the evaporator and return it to the compressor, whereby the circulation of the refrigerant through the evaporator is unimpaired.

Another object of the invention is to provide an improved evaporator for a refrigeration apparatus having an inlet and an outlet, formed of relatively thin sheets of metal having a high co-eflicient of heat conductivity and at least one thereof being provided with spaced embossed portions xed to the other plate in a predetermined arrangement to provide therebetween a plurality of refrigerant flow channels of limited area in cross section, whereby the suction effect due to operation of the compressor insures rapid ow of the refrigerant through the evaporator and efficient absorption of heat units and upon starting of the apparatus, after a shut-down thereof, the accumulated oil in the evaporator is along with the vaporized refrigerant to the compressor.

Another object of the invention is to provide an improved evaporator consisting of related relatively thin sheets of metal one of which is provided with uniformly disposed embossments to form between the metal sheets relatively small flow passages, outlet connections for vapor on one edge of the evaporator, inlet connections for the refrigerant on another edge of the evaporator and a baille extending parallel to but spaced from the discharge edge of the evaporator to provide a drying chamber for the gasifled refrigerant, so that no liquid refrigerant is removed from the evaporator with the vapor as the latter flows to the compressor.

Another object of the invention is to construct an improved evaporator formed of substantially parallelly spaced plates, one of which is embossed relative to the other plate to form elongated connected flow channels between the lateral edges of the evaporator and provided with means for supplying the refrigerant to one end of these channels and discharge of the vapors from the other end thereof in a manner which insures substantially uniform circulation of the refrigerant throughout the entire evaporator and balanced suction effect from the compressor.

Another object of the invention is to provide an improved refrigeration apparatus comprising a cabinet and an evaporator therein consisting of a refrigerant circulation unit spaced from the bottom of the cabinet and having sections spaced from but disposed parallel to the inner walls of the cabinet to permit circulation of air Within the cabinet around the outer side of the evaporator and throughout the products being refrigerated.

Another object of the invention iS to construct an improved evaporator for a refrigeration apparatus having an inlet and an outlet, formed of relatively thin sheets of metal and at least one thereof being provided throughout its area with spaced rows of elongated embossments, the embossments in each row being in end-to-end relation and spaced a greater distance than the spacing between the rows of said embossments, to form flow channels, supply connections for refrigerant at one side of the evaporator for the channels formed between the ends of the embossments and outlet connections for the vapor discharged from said channels at another side of the evaporator.

Another object of the invention ls to construct rapidly and completely picked up and carried an improved evaporator for a refrigeration apparatus having an inlet and an outlet formed of relativey thin sheets of metal having a high co-eilicient of heat conductivity and at least one thereof being provided with spaced embossed portions xed to the other plate in a predetermined arrangement to provide therebetween a plurality of vertical and horizontal refrigerant flow channels, the cross sectional area of the horizontal channels being less than that of the vertical channels, to thereby induce an increased flow in the horizontal channels.

Another object of the invention is to construct an improved evaporator of the type referred to comprising related plates having spacedly related Walls between them for dividing the space between the plates into refrigerant circulation channels of small area in cross section, whereby a large portion of the refrigerant within and in circulation therein is in direct contact with the walls of the plates to effect maximum absorption of heat by conduction therethrough.

Another object of the invention is to provide an improved refrigeration apparatus consisting of a cabinet having compartments, each containing a refrigerant circulation unit, connected with a refrigerant supply and a compressor and means for controlling the connections with the compressor, whereby the temperature in one compartment is maintained below that in the other compartment.

Other Objects of the invention will be apparent to those skilled in the art to which my invention relates from the following description taken in connection with the accompanying drawings, wherein Fig. 1 is a section on the line I I of Fig. 2 showing an apparatus embodying my invention.

Fig. 1a. is a diagrammatic view of the evaporators and the refrigerant connections thereto and outlet connections therefrom.

Fig. 2 is a section on the line 2 2 of Fig. 1.

Fig. 3 is a view of a portion of one of the evaporators, parts being broken away.

Figs. 4, 5, 6, 7, 9 and 10 are sections on the lines 4 4, 5 5, 6 6, 1 1, 9 9 and Ill-I0, respectively, of Fig. 3.

Fig. 8 is an end elevation on the line 8 3 of Fig. 3.

Fig. 11 is a fragmentary section on the line 2 2 of Fig. l, enlarged.

Fig. 12 is a side elevation of one of the evaporators before it is bent into final form.

Fig. 13 is a side elevation of one of the other evaporators before it is bent into nal form.

Fig. 14 is a fragmentary view of a portion of one of the evaporators, enlarged.

Fig. 15 is a fragmentary view of a portion of one of the evaporators, enlarged.

Fig. 16 is a section on the line lli-I6 of Fig. 15.

Fig. 17 is an elevational view of an evaporator showing a modied form of construction.

Fig. 17a is a section on the line lla- Ila of Fig. 17.

Fig. 18 is an elevational View of another form of evaporator as fabricated ready for shaping into final form for assembly in a cabinet.

Fig. 19 shows a cabinet (the door being broken away) and the evaporator, after shaping thereof, assembled in the cabinet.

In the drawings, I indicates as an entirety a cabinet of any desired size and construction, the walls of the cabinet being insulated in a well known manner. Preferably the inner walls of the cabinet are lined with sheet metal la and its exterior walls are provided with a suitable facing material lb; the lining and facing materials may be utilized to protect the insulation material against deterioration and damage. In the exemplified disclosure herein, the cabinet is provided with a partition Ic (also suitably insulated against the conduction of heat) thereby forming two freezing compartments 2, 3, one of which is maintained at a temperature lower than that of the other compartment to provide a compartment known as a deep freeze space. For purposes of identification, the compartment 2 will be referred to as the main freezing compartment and the compartment 3 as the deep freeze compartment. The top wall of the cabinet is formed with openings Id, the top wall and openings being preferably surfaced with thin non-corrosive material Id. 4 indicates the lids for the openings Id, each lid being provided on the lower side of its marginal portion with a. non-metallic material 4a to eliminate metal-to-metal contact with the cabinet walls, when the lids 4 are in closed position, as shown in Fig. 2.

5 indicates as an entirety an evaporator for the main freezing compartment 2 (see Fig. 12). The evaporator 5 is bent on transverse lines to provide sections parallel and closely adjacent to the inner side walls of the compartment 2, but slightly spaced therefrom for circulation of air exteriorly of the evaporator. In this shape of the evaporator maximum space within the compartment 2 may be utilized for storage purposes. The opposite ends of the evaporator 5 terminate adjacent the open end of a pocket 5a preferably formed in one of the cabinet walls, to which access may be provided for in any suitable manner. The expansion valves (later referred to) are mounted in the pocket and surrounded by suitable heat insulation material to protect them from the refrigerated atmosphere in the cabinet. 6 indicates devices for supporting the evaporator 5 on the bottom wall of the compartment 2, but in spaced relation thereto, so that air may circulate from side to side of the compartment. I preferably provide a supporting device 6 for each side section of the evaporator 5. Each device 6 is formed of a section of slightly resilient sheet metal having a vertical leg 6a the upper portion of which terminates in reversely bent portions 6b, forming between them a groove to removably receive the lower edge of the evaporator 5. The side walls of the groove yieldingly engage the opposite faces of the evaporator 5. The devices 6 are mounted on the lower r edge of the evaporator 5 before it is positioned in the compartment 2 and remain attached thereto when the evaporator for any reason is removed from the compartment.

1, 8, indicate upper and lower evaporators mounted in the deep freeze compartment 3. The evaporators 5, 1 and 8 are of similar construction (as later set forth), but of different shape to t the compartments 2, 3, of the illustrated cabinet; howet er, each evaporator may be of any desired lengthand width and bent intermediate its ends or side edges into various shapes dependent on the interior construction of the cabinet and/or the kind or arrangement of the commodities to be stored in each compartment.

The upper evaporator 1 is a U-shaped and preferably supported on the elevated section I of the cabinet I. By making the evaporator U- shaped its bottom section 'la is parallelly related to but spaced from the partition Ic and its legs 1b, 1b, are parallelly related to and spaced from the front and rear walls of the compartment 3. The evaporator 8 consists of an outer vertical end section 8a, and parallelly related to but SUIKUH KUUWI spaced from the adjacent end wall of the compartment 3, an inner vertical end section 8b parallel to but spaced from the partion Ic and an intermediate horizontal section 8c. The intermediate section 8c engages the cabinet wall I' to support the evaporator 8 in the compartment 3. The sections 8a and 8c of the evaporator 8 extend be- .tween the legs Ib of the evaporator 1. In this arrangement (a) storage spaces are provided in the compartment 3 within the sections 1a, 1b, of the evaporator l and between the inner end section 8b of the evaporator 8 and the partition Ic, both spaces being accessible through the opening 1d for the compartment 3 and (b) the space below the cabinet wall I forms exteriorly of the cabinet a chamber I0, which may be utilized for a condenser unit (not shown) necessary for carrying out the refrigerant cycle already referred to.

Figs. 12 and 13 illustrate the evaporators 5 and 'I as fabricated ready to be bent on transverse lines to iit the compartments 2, 3; the evaporator 8 is similarly fabricated before being bent to the shape shown in Figs. l, 1a and 2. It will be observed however that the evaporator, as fabricated, may be bent on longitudinal lines where the cabinet or other structure therefor make such an arrangement desirable. The evaporators herein shown are similar in construction, except for slight differences in the connections of the supply pipes for the refrigerant and outlets for the vapor. Any suitable refrigerant usually employed in mechanical refrigerators (for example a compound known as Freon) may be employed.

Referring to Figs. 3 to 10, inclusive, the evaporator consists of two plates 5.1:, 5x', in side by side relation, the marginal end edges and longitudinal edges of which are xedly sealed (preferably welded) together, as shown at 5x" (Figs. 9 and 10). The plates 5x, 5x', are formed of thin sheet metal (preferably approximately 16 gage although thicker or thinner gage metal may be used when found desirable) formed of steel, aluminum or other sheet stock.

One of the plates, for example, the plate 5.7:, adjacent its upper longitudinal edge, Within the weld 5r, is embossed to form a conduit I I, to serve as the outlet or exhaust for the vapor. 'I'his outlet or conduit preferably extends from end to end of the evaporator 5 and is connected by spaced exhaust ducts IIa with the circulation channels within the evaporator as later set forth. The vapor is discharged from the conduit I I through outlet nipples arranged, in connection with the exhaust ducts, to insure an efdcient balanced suction effect within and over the entire area of the evaporator, but in the disclosed construction the opposite ends of the conduit I I are provided with nipples I2, suitably connected to pipes I2a (see Fig. 1a) which, through a T-iitting I2b, arel connected to a pipe I3, the latter in turn being connected to the intake side of a suitable compressor I4. The plates 5r, 5x' are sealed (preferably welded) together below and parallel to the conduit II from end to end, as shown at 5y, except at intermediate positions to provide for a plurality of exhaust ducts IIa leading from the interior of the evaporator 5 to the conduit II.

The plate 5x is provided throughout its area between the welds 5x and 5y with horizontally extending elongated embossments, each indicated at I8, arranged in vertical and horizontal rows to provide therebetween circulation channels for the refrigerant and vapor; that is, (a) the vertical rows of embossments I8 are uniformly spaced in side-by-side relation from end to end of the evaporator l with the embossments in each row in alinement, (b) the embossments in each row are uniformly spaced; and (c) each embossment I8 in each vertical row is in horizontal alinement with one embossment of each of the remaining vertical rows. In this arrangement (a) a refrigerant supply conduit I1 is formed between the lower horizontal row of embossments I6 and the adjacent weld 5x in connected relation with each of the channels I8 which are formed between the vertical rows of embossments Il and the welds 5.1: at the ends of the evaporator, which channels I8 are connected to the channels I8 formed between the horizontal rows of embossments I6; and (b) a channel IIa is formed between the upper horizontal row of embossments I6 and the weld 5y, this channel having connection with the upper ends of all of the vertical channels I8. As shown. the supply conduit I1 is of larger capacity than the channels I8, I8. The plate 5x' at the opposite ends of the supply conduit I 1 is embossed laterally to form seats in which nipples 20 are suitably secured. The nipples 28 are connected to pipes 28a (see Fig. 1a). which, through a T-fitting 2Gb, are connected to a pipe 20c leading from a liquid refrigerant receiver 2 I. 22 indicates a suitable expansion valve in the pipe 20c.

Each of the embossments` I6 is shaped to provide a flat base IGa having curved end walls (for a purpose later set forth), the base being in face-to-face relation to the plate 51: and fixed thereto by a weld indicated at lib. The embossments I6 have a lateral displacement approximating .091 of an inch which determines the spacing between the plates 51:, 5x', more particularly the distance between the plate 5a: and the inner crown portion of each of the channels I8, I9. In this form of embossment the opposed end walls of adjacent embossments form the channels I8 between the vertical rows of embossments and the elongated opposed side walls of adjacent embossments form the channels I8 between the horizontal rows of embossments.

As shown, the vertical rows of embossments I8 are closely related and likewise the horizontal rows of embossments are closely related, thereby forming channels I8 and I9, each having a small cross sectional area; also. it will -be observed that the cross sectional area of the channels I9 is materially reduced as compared to that of the channels I8 and that as the embossments I8 have curvilinear end walls the openings at the opposite ends of the channel I9 between adjacent embossments are enlarged for purposes later set forth. The embossments I6 are approximately one and three-fourth inches long and approximately thirteen sixteenth inches wide; the spacing between opposed ends of adjacent embossments (maximum width of the channels I8) is approximately seventeen sixteenth inches; and the spacing between the elongated sides of the embossments (maximum width of the channels I9) is approximately thirteen sixteenth inches. The arrangement, shape and spacing of the embossments I6 are advantageous as the supplied liquid refrigerant is sub-divided into a multitude of small circulating streams,

each of small volume in cross section in direct contact with the opposed walls of the channels I8, I9, which walls therefore form prime pick-up areas, so that rapid absorption of heat, with resulting gasification of the liquid, takes place. As the bases I8a of the embossments I8 occupy the remaining portion of the evaporator l and serve as secondary pick-up areas, it will be seen that all portions of the walls 5r, 5m', between the welds 5x, 5y, are subject to the heat absorbing property of the refrigerant.

The outlet ducts IIa connect the channel IIa with the conduit II and are spaced from end to end of the evaporator 5 to provide a balanced suction effect, due to operation of the compressor I4, in withdrawing the vapor from the evaporator 5. By preference the outlet duct IIa most remote from the nipples I2 is larger in size than the remaining outlet ducts to maintain a balanced suction effect upon the entire evaporator. The number, capacity and spacing of the outlets may be varied to insure complete discharge of the vapor,

23 indicates as an entirety baffling means extending parallel to but spaced from the channel Ila, whereby the channels I8, I9, between the baffling means and channel Ila serve as a drying space or chamber for those portions of the liquid not gasied before flowing around the baling means. As such portions flow through a large number of channels of small cross sectional area, gasification or vaporization thereof is completed in this space to avoid wet gas entering the conduit Il. In the form of construction shown in Figs. 1 to 15, inclusive, the baffling means 23 consist of spaced sections of suitable material 23' in endwise relation and mounted in one of the horizontal channels I9 formed between adjacent embossments I6 remote from the conduit II. The material 23' may have a cross sectional shape equal to that of the channel. I have illustrated round sections 23', which may be formed of metallic or non-metallic material, the diameter of the section being of a size to ll the space between the plate 53: and the crown portion of the 4channel I9 (see Fig. 10) and close the channels I8 between the opposite ends of each section. The outer ends f the outer baffles 23 are spaced from the adjacent welds 5m and the intermediate bailles are arranged to position their opposed spaced ends in line with certain of the channels I8 and out of line with the outlet ducts I la. In this arrangement the larger portion of the refrigerant and -bubbles of vapor mixed therewith aredirected around the baffles 23 into the channels I8, I9, thereabove, and

hence prevented from flowing from the channels I8 below the baffles directly to the channels I8, I9 above them.

In tfe form of baffle means 23 shown in Figs. 1'7 and 17a, I provide alined spaced sections of continuous welds 23" between the plates 5r, 5x', preferably extending between two adjacent horizontal rows of embossments I6 remote from and parallel to the collecting channel Ila. The spacing between the baffles 23" and the welds 5m" are arranged similarly to that of the wire sections 23. As shown, the plate 5cc' is embossed laterally as shown at 23x for engagement with the plate 5:: and then continuously welded. Each of the outer baffles 23" starts at a point remote from the adjacent end weld 5.1: and extends relative to two or more embossments I6 to close the channels I8 therebetween; lthe intermediate baffles 23" extend relative to two or more embossments I6 to close the channels I8 therebetween and are spaced from each other and the outer baffles 23" so as to leave certain of the channels I8 o pen for flow of the refrigerant and vapor therethrough. v

As already set forth, the embossments I6 are horizontally elongated so that the interior surfaces of their upper side walls form ledges |53: on which oil utilized for operation of the compressor and mixed with the refrigerant collects, when the apparatus is shut down. As will be understood, during operation of the apparatus the oil which becomes mixed with the refrigerant is separated therefrom as vaporization takes place and is returned with the vapor to the compressor; but when the apparatus is shut down the oil in the liquid portion of the refrigerant remains suspended therein, whereas the separated portion of the oil collects on the ledges Ix. When the apparatus is again operated, the oil collected on the ledges Ilia: adheres to the bubbles of vapor incident to the circulation of the refrigerant through the channels I8 and I9 and is returned with the vapor to the compressor. As a large number of ledges I6a: are provided, the total amount of oil collected thereon is spread in film form over a large area, so that all of the collected oil is picked up in a short period of time upon starting of the compressor. To insure complete pick-up of the oil collected on the ledges Isar, the cross sectional area of the channels I9 is materially smaller than that of the channels I8, so that the suction effect of the compressor provides a differential pressure with respect to the flow of the refrigerant and vapor in the channels I9 as compared to the pressure in the channels I8, whereby the pull of the refrigerant and vapor in the channels I8 on the refrigerant and vapor in the channels I9 induces an increased rate of flow in the latter channels, with the result that the collected oil on the ledges |60: is readily picked up by the refrigerant and Vapor and carried along therewith and returned to the compressor. Also, by reason of the curved end walls of the embossments, which form diverging openings connecting the channels I9 with the channels I8, frictional losses which would affect the pull effect of the refrigerant and vapor circulating in the channels I8 yon the refrigerant and vapor circulating in the channels I9, are minimized and thus increases the pull effect on the refrigerant and vapor in the channels I9 to insure a ready pick up of the oil from the ledges IS when the apparatus is started up.

It will be understood that when the evaporators 5, 'I and 8 are shaped into the forms illustrated, the embossed walls 5.1: may be on the inner sides or faces thereof, but preferably these walls are on the outer sides or faces of the evaporators, so that the plates 5m, which are smooth throughout their areas, may be readily cleaned from time to time.

The refrigerant from the receiver 2I for the evaporators I and 8 is supplied through a pipe 24 connected to the pipe 28C, the pipe 24 being connected by branch pipes 24a, 24h, to the evaporators 1, 8, respectively. 25 indicates an expansion valve in the pipe 24. The pipe 24a is connected to a nipple 26 mounted in the wall 5.1: of the evaporator I at the bottom and intermediate the ends thereof. The vapor conduit II for the evaporator 'I is provided intermediate its ends with a nipple 21 which is connected to a return pipe 21a, the latter in turn being connected to the pipe I3. The pipe 2417 is connected to a nipple 28 mounted in the wall 5x of the evaporator 8 between its side edges and adjacent the lower end of the section 8b. The vapor conduit II for the evaporator 8 s provided at its outer end with a nipple 29, which is connected to a pipe 29a, the latter in turn being connected to the pipe 21a. 30 indicates an adjustable con- QLHHLIH NUUWI stant pressure valve of well known construction, in the pipe I3 between the pipe 21a and outlet nipples I2 for the evaporator 5, and serving to control the temperature in the latter above that of the evaporators I and 8.

The metal sheets for each evaporator 5, 1 and 8 are cut to a predetermined size. One sheet (53:) is embossed al-ong but remote from one edge to form the side wall of the conduit II. The other sheet (5cc) is subjected to the coaction of suitable dies to form the embossments I6. Due to the length of the sheet 5x', I have found it preferable to form one or more vertical rows of embossments (as viewed in Figs- 12 and 13) and to then adjust the sheet and form the adjacent row or rows of embossments, this operation being repeated throughout the length of the sheet. The operation of forming the embossments provides the channels I8, I9, the outer walls of which are curvilinear in cross section. Next the marginal portions of the sheet 51: above and below the vertical rows of embossments and along the outermost rows thereof are displaced laterally to position these marginal portions for engagement with the marginal portions of the sheet 5a: and to form the side walls of the channels -I'I, I'Ia; this last identied step may include the necessary embossment for the nipples. Next, the sheet 5x' is passed through a set of suitable leveling rolls to straighten the sheet and remove stresses developed therein due to the embossing operations. Next the sheets 5x, 5.7:', and baffles 23 are assembled, ,and secured together. In carrying out this assembly step the sheets are first tack welded and thereafter seam-welded as shown at 5x. Finally, the embossments I6 are welded (preferably seam welded throughout the areas ISb) to the sheet 5x. The evaporator is completed by mounting the inlet and outlet nipples therein and it may then be tested, cleaned, coated with a material to prevent oxidation and bent into a desired shape, examples of which are herein shown for illustrative purposes.

Fig. 18 illustrates a refrigerating apparatus of modified form, wherein the evaporator is bent into a different shape, as compared to the evaporators 5, 'I and 8 and the embossments are provided throughout a predetermined area on one of the sheets and throughout a predetermined area on the other sheet (see Fig. 18), for reasons later apparent, whereby a plurality of storage spaces for edibles and bottled goods are provided by the employment of a single evaporator. In Fig. 19, 3| indicates a cabinet having insulated walls of any desired construction, the front of the cabinet being open and provided with a door 3Ia. 32 indicates an evaporator consisting of related sheets 5x, 5x (as already described) having upper and lower` end sections 32a, 32a', related to one side wall of the cabinet 3 I, intermediate outer and inner L-sections 32h, 32o, and a section 32d connecting the vertical legs of the sections 32h, 32e. The vertical leg of the section 32h is related to the other side wall of the cabinet 3|, whereas the section 32d rests on the bottom of the cabinet. In this shaped evaporator, a storage space 33 is provided between the end section 32a, the horizontal leg of the section 32b and the adjacent cabinet walls, a storage space 34 is provided between the sections 32h, 32e and a storage space 35 is provided within the sections 32a', 32c. As it is desirable to provide as far as possible smooth inner walls for the storage spaces, to facilitate cleaning thereof, the embossments I6 are provided on that portion of one sheet which is on the outer side of the end section 32a and lower side of the horizontal leg of the L-section 32D, whereas the other sheet throughout the remaining portion of the evaporator is provided with embossments I6. Fig. 18 shows the evaporator 32 as completed ready to be bent into the shape shown in Fig. 19.

Figs. 18 and 19 illustrate one example of an evaporator having a predetermined embossed area, each of the sheets which form the evaporator 32, being so arranged that the embossed area of each sheet is related to an un-embossed area of the other sheet, but it will be understood that either or both plates may be provided with two or more embossed areas dependent on the size and shape of the cabinet and/or the number and arrangement of the storage spaces to be provided therein.

This application is a continuation in part of my copending application Serial No. 529,500, led April 4, 1944.

To those skilled in the art to which my invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope thereof. My disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

What I claim is:

1. In apparatus of the class described, the combination with a cabinet having an opening and a closure therefor, of an evaporator consisting of a pair of spaced plates provided with embossments forming therebetween channels for the circulation of a volatile liquid, said evaporator being shaped to form upper and lower alined end sections adjacent to one wall of said cabinet, an outer L-shaped section connected at one end to said upper end section, an inner L-shaped section connected at one end to the opposite end of said outer L-shaped section and a separate section between the opposite end of said inner L-shaped section and said lower end section, said L-shaped sections forming between them a storage space and portions of each AL-shaped section forming with the adjacent cabinet walls a separate storage space, the embossments in those portions of said plates which form the bottom and sides of the storage space between said L-shaped sections being disposed on the outer sides thereof, one of said end sections having an inlet for the liquid and the other end section having an outlet for vapor.

2. An evaporator consisting of a pair of plates sealingly connected along their marginal edges, a portion of one plate within the marginal edges thereof being embossed to form with the adjacent opposed portion of the other plate vertically and horizontally extending circulating channels therebetween for a volatile liquid and another portion of the other plate within the marginal edges thereof being embossed to form with the adjacent opposed portion of the rst mentioned plate vertically and horizontally extending circulating channels therebetween for the volatile liquid, said embossments being elongated at right angles to said vertical channels, a liquid supply channel along one end of the evaporator connected with the adjacent ends of the vertical channels, and a conduit for vapors along the opposite end of the evaporator connected to the opposite ends of the vertical channels.

3. In apparatus of the class described, the combination with a cabinet, of an evaporator consist- 'ng of a pair of closely related sheet metal plates provided with means for forming between them vertically and horizontally extending circulating channels for a volatile liquid refrigerant and a conduit for vapors extending along the upper end of said evaporator, means for supplying the liquid refrigerant to the lower ends of the vertical channels, spaced outlets leading from the upper ends of said vertical channels to said conduit,- and endwise related spaced ballles disposed parallel to said horizontal channels in remote relation to said outlets, the spaces between the opposed ends of said baiiies being out of alinement with said outlets, said evaporator being bent intermediate its ends to form contiguous sections each parallelly related to one inner side wall of said cabinet.

4. In apparatus of the class described, the combination with a cabinet, of an evaporator mounted in said cabinet and consisting of a pair of closely related sheet metal plates provided with means for forming between them vertically and horizontally extending circulating channels for a volatile liquid refrigerant and a conduit for vapors extending along the upper end of said evaporator and having an outlet nipple adapted to be connected to a compressor, means for supplying the liquid refrigerant to the lower ends of the vertical channels, spaced outlets leading from the upper ends of certain of said vertical channels to said conduit, the outlet most remote from said outlet nipple being larger than the remaining outlets, and endwise related spaced baliies disposed parallel to said horizontal channels in remote relation to said outlets.

5. An evaporator comprising a pair of sheet metal plates the marginal side and end portions of which are sealingly connected, one of said plates within the marginal portions thereof being provided with spaced rows of elongated embossments in endwise spaced relation forming now channels between adjoining rows, each elongated embossment in each row terminating in curvilinear end walls and being alined with the adjacent upper and lower elongated embossments in the adjoining rows, whereby iiow channels are provided between the rows of alined elongated embossments, the spacing of the alined rows of elongated embos-sments being greater than the spacing of the rows of elongated endwise related embossments, means for supplying a refrigerant to the last mentioned flow channels at one end thereof, and outlet means yfor vapor connected to the last mentioned flow channels at the other end thereof.

6. An evaporator comprising a pair of sheet metal plates the marginal side and end portions of which are sealingly connected, one of said plates within the connected marginal portions thereof being .provided With uniformly spaced horizontal rows of uniformly spaced embossments connected to the other plate and forming between them horizontally disposed flow channels, each embossment in each horizontal row being in vertical alinemen-t with the adjacent embossments in adjoining rows to forni vertical ow channels between the opposed ends of the vertically alined embossments, means for supplying a refrigerant to the lower ends of the last mentioned channels, outlet means for vapor consisting of a horlzontally disposed conduit between the upper sealingly connected side and the upper horizontal row of embossments, said .plates between the upper ends of said last mentioned channels and said conduit being welded together along spaced inl2 tervals parallel to said conduit to form outlets between said welded together portions for the upper ends of said last mentioned flow channels,

7. An evaporator comprising a pair of sheet metal plates the marginal side and end portions of which are sealingly connected, one of said plates wi-thin the connected marginal portions thereof being provided with uniformly spaced horizontal rows of embossments, said embossments being elongated horizontally and connected to the other .plate and forming between them horizontally disposed now channels for a refrigerant, the embossments in each row being uniformly spaced and each being in vertical alinement `with the adjacent embossments in the adjoining rows to form vertically disposed now channels, and outlet means for vapor consisting of a horizontally disposed conduit adjacent the upper marginal sealed side of the evaporator, a. separate channel remote from and disposed parallel to said conduit and connected to the upper ends of said last mentioned flow channels and spaced outlets leading from said separate channel to said conduit, and endwise related, spaced sectional baiiling means between said plates remote from and parallel to said separate channel, the spacing between the sections of the bafing means being out of alinement of said spaced outlet-s.

8. An evaporator as claimed in claim 7 wherein said baffling means consist of endwise related, spaced sections of rod extending through the channel between adjacent horizontal rows of embossments remote from said separate channel, the spacing between said rod sections being out of alinement with said spaced outlets.

9. An evaporator comprising a -pair of sheet metal plates the marginal side and end portions of which are sealingly connected, one of said plates within the connected marginal portions thereof being provided with uniformly spaced horizont-al rows of embossments, said embossments being elongated horizontally and -connected to the other plate and forming between them horizontally disposed ow channels for a refrigerant, the embossments in each row being uniformly spaced and each being in vertical alinement with the adjacent embossments in the adjoining rows, outlet means for vapor consisting of a horizontally disposed conduit adjacent to the upper marginal sealed side of the evaporator, a separate channel remote from and disposed parallel to said conduit and connected to the -upper ends of said last mentioned flow channels and spaced outlets leading from said separate channel to said conduit, and baflling means remote from and parallel to said separate channel and consisting of spacedly alined welds between the plates, each weld being co-extensive with a. plurality of horizontally related embossments, the spacing :between the welds being out of alinement with said spaced outlets.

CHARLES C. HUBBELL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,549,619 Steenstrup Aug. 11, 1925 2,349,695 Beane May 23, 1944 2,380,987 Morrison Aug. 7. 1945 

